org.jboss.modules.ModuleIdentifier Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.modules;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.lang.reflect.Field;
import java.security.AccessController;
import java.security.PrivilegedAction;
/**
* A unique identifier for a module within a module loader.
*
* @author John Bailey
* @author David M. Lloyd
* @author Jason T. Greene
*
* @apiviz.landmark
*/
public final class ModuleIdentifier implements Serializable {
private static final long serialVersionUID = 118533026624827995L;
private static final String DEFAULT_SLOT = "main";
private final String name;
private final String slot;
private final transient int hashCode;
private static final Field hashField;
static {
hashField = AccessController.doPrivileged(new PrivilegedAction() {
public Field run() {
final Field field;
try {
field = ModuleIdentifier.class.getDeclaredField("hashCode");
field.setAccessible(true);
} catch (NoSuchFieldException e) {
throw new NoSuchFieldError(e.getMessage());
}
return field;
}
});
}
/**
* The class path module (only present if booted from a class path).
*/
public static final ModuleIdentifier CLASSPATH = new ModuleIdentifier("Classpath", DEFAULT_SLOT);
private ModuleIdentifier(final String name, final String slot) {
this.name = name;
this.slot = slot;
hashCode = calculateHashCode(name, slot);
}
private static int calculateHashCode(final String name, final String slot) {
int h = 17;
h = 37 * h + name.hashCode();
h = 37 * h + slot.hashCode();
return h;
}
/**
* Get the module name.
*
* @return the module name
*/
public String getName() {
return name;
}
/**
* Get the module version slot.
*
* @return the version slot
*/
public String getSlot() {
return slot;
}
/**
* Determine whether this object is equal to another.
*
* @param other the other object
* @return {@code true} if they are equal, {@code false} otherwise
*/
public boolean equals(Object other) {
return other instanceof ModuleIdentifier && equals((ModuleIdentifier)other);
}
/**
* Determine whether this object is equal to another.
*
* @param other the other object
* @return {@code true} if they are equal, {@code false} otherwise
*/
public boolean equals(ModuleIdentifier other) {
return this == other || other != null && name.equals(other.name) && slot.equals(other.slot);
}
/**
* Determine the hash code of this module identifier.
*
* @return the hash code
*/
@Override
public int hashCode() {
return hashCode;
}
/**
* Get the string representation of this module identifier.
*
* @return the string representation
*/
@Override
public String toString() {
return escapeName(name) + ":" + escapeSlot(slot);
}
private void readObject(ObjectInputStream ois) throws ClassNotFoundException, IOException {
ois.defaultReadObject();
try {
hashField.setInt(this, calculateHashCode(name, slot));
} catch (IllegalAccessException e) {
throw new IllegalAccessError(e.getMessage());
}
}
private static String escapeName(String name) {
final StringBuilder b = new StringBuilder();
boolean escaped = false;
int c;
for (int i = 0; i < name.length(); i = name.offsetByCodePoints(i, 1)) {
c = name.codePointAt(i);
switch (c) {
case '\\':
case ':':
escaped = true;
b.append('\\');
// fall thru
default:
b.appendCodePoint(c);
}
}
return escaped ? b.toString() : name;
}
private static String escapeSlot(String slot) {
final StringBuilder b = new StringBuilder();
boolean escaped = false;
int c;
for (int i = 0; i < slot.length(); i = slot.offsetByCodePoints(i, 1)) {
c = slot.codePointAt(i);
switch (c) {
case '\\':
escaped = true;
b.append('\\');
// fall thru
default:
b.appendCodePoint(c);
}
}
return escaped ? b.toString() : slot;
}
/**
* Parse a module specification from a string.
*
* @param moduleSpec the specification string
* @return the module identifier
* @throws IllegalArgumentException if the format of the module specification is invalid or it is {@code null}
*/
public static ModuleIdentifier fromString(String moduleSpec) throws IllegalArgumentException {
if (moduleSpec == null) {
throw new IllegalArgumentException("Module specification is null");
}
if (moduleSpec.length() == 0) {
throw new IllegalArgumentException("Empty module specification");
}
int c;
final StringBuilder b = new StringBuilder();
int i = 0;
while (i < moduleSpec.length()) {
c = moduleSpec.codePointAt(i);
if (c == '\\') {
b.appendCodePoint(c);
i = moduleSpec.offsetByCodePoints(i, 1);
if (i < moduleSpec.length()) {
c = moduleSpec.codePointAt(i);
b.appendCodePoint(c);
} else {
throw new IllegalArgumentException("Name has an unterminated escape");
}
} else if (c == ':') {
i = moduleSpec.offsetByCodePoints(i, 1);
if (i == moduleSpec.length()) {
throw new IllegalArgumentException("Slot is empty");
}
// end of name, now comes the slot
break;
} else {
b.appendCodePoint(c);
}
i = moduleSpec.offsetByCodePoints(i, 1);
}
final String name = b.toString();
b.setLength(0);
if (i < moduleSpec.length()) do {
c = moduleSpec.codePointAt(i);
b.appendCodePoint(c);
i = moduleSpec.offsetByCodePoints(i, 1);
} while (i < moduleSpec.length()); else {
return new ModuleIdentifier(name, DEFAULT_SLOT);
}
return new ModuleIdentifier(name, b.toString());
}
/**
* Creates a new module identifier using the specified name and slot.
* A slot allows for multiple modules to exist with the same name.
* The main usage pattern for this is to differentiate between
* two incompatible release streams of a module.
*
* Normally all module definitions wind up in the "main" slot.
* An unspecified or null slot will result in placement in the "main"
* slot.
*
* Unless you have a true need for a slot, it should not be specified.
* When in doubt use the {{@link #create(String)} method instead.
*
* @param name the name of the module
* @param slot the slot this module belongs in
* @return the identifier
*/
public static ModuleIdentifier create(final String name, String slot) {
if (name == null)
throw new IllegalArgumentException("Name can not be null");
if (slot == null)
slot = DEFAULT_SLOT;
return new ModuleIdentifier(name, slot);
}
/**
* Creates a new module identifier using the specified name.
*
* @param name the name of the module
* @return the identifier
*/
public static ModuleIdentifier create(String name) {
return create(name, null);
}
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